Salivary gland infections (bacterial or viral sialadenitis) are not uncommon. The most frequently encountered infection of the salivary glands is caused by the mumps virus. However, a number of other agents, particularly bacteria, are responsible for acute sialadenitis.

The parotid glands are more commonly infected than the submandibular salivary glands and consequently most reports deal with bacterial parotitis, although the submandibular glands may be similarly affected. Infections of the accessory salivary gland can occur but are very rare (Table 11.1). Apart from mumps, the majority of salivary gland infections are seen in adults. However, there are two rather ill-defined clinical entities termed neonatal suppurative parotitis and recurrent parotitis of childhood (chronic juvenile parotitis) which are confined to the first decade of life.

As in many other infectious diseases, initiation and progression of salivary gland infections would appear to depend on the host resistance to infection and the virulence of the causative organism(s). The decrease in host resistance in the present context could be either due to general factors such as debility and dehydration or due to local factors including sialolithiasis, ductal strictures and salivary gland pathology. Factors important in salivary gland infections are shown in Figure 11.1.